Page 1 of 2

replace battery in NV-RAM ST timekeeper MK48T08B-15

Posted: Mon Jul 18, 2005 3:17 pm
by XCLTempesT
SO I wondered if it is possible to just replace the battery inside the Timekeeper module in the CDI. (in a MK48T08B-15 ST NV-ram timekeeper for expample).

I know I could replace it with a new module, but adding an easily replacable battery has a bit more charm.

On the net I came across some site about hackking a different model timekeeper: the M48T02 module:

http://www.bhargavaz.net/nvram/nvram.html
http://www.jmargolin.com/rdy2k/hdzram.htm

but these modules are a bit different (they have only 24 pins, the 48T08 has 28 ), so do you think that I could hack a 48T08 in the same way? Do you need any programing/formatting, in order for a new module (or a module with a replaced battery) to work with in a CDI systems? In these SUN systems in the guides above, they first have to programe the chips before the SUN systems can use them, does the CDI system do a Autoformat if an empty NV-ram module is detected?

I also came across a japanese site about hacking a MK48T18 (isn;t that used in later models CDI players?). unfortunately I don't understand a word of Japanese (anyone here that does?):
http://www.znet.or.jp/~clare/nvram/

If I were to replace the timekeeper module, could I replace it with a module with more memory (32kB NV-RAM, like the newer cd-i player versions).Or is the amount of usable NV-RAM hardcoded in the players operating system?
many thanx

Posted: Mon Jul 25, 2005 8:50 pm
by metalsphere
To translate that page into english just go here http://world.altavista.com/ and paste in the url and choose japanese to english. I just tried it and it works great.

Posted: Mon Jul 25, 2005 9:29 pm
by Erronous
If replacing an old NVRAM with a new NVRAM will work, soldering a new battery to an old NVRAM should also work. The replacement NVRAM chips also don't come pre-programmed. I would guess this sort of thing would be documented in the Green Book. Some NVRAM chips also have an external battery connector, but I don't remember if this was also true for the ones used in CD-i players.

Posted: Tue Jul 26, 2005 10:11 pm
by Devin
Erronous wrote:If replacing an old NVRAM with a new NVRAM will work, soldering a new battery to an old NVRAM should also work. The replacement NVRAM chips also don't come pre-programmed. I would guess this sort of thing would be documented in the Green Book. Some NVRAM chips also have an external battery connector, but I don't remember if this was also true for the ones used in CD-i players.
So would the NV-RAM be auto-formatted when put in the CD-i player fresh seems to be the question?

Posted: Wed Jul 27, 2005 9:13 pm
by cdifan
All player ROMs I've seen so far will indeed autoformat the contents of the NVRAM (at least under emulation...).

PS. I'm currently on vacation and using a Cybercafe; don't expect prompt replies :-)

Posted: Wed Jul 27, 2005 9:23 pm
by Devin
cdifan wrote:All player ROMs I've seen so far will indeed autoformat the contents of the NVRAM (at least under emulation...).

PS. I'm currently on vacation and using a Cybercafe; don't expect prompt replies :-)
So they have the wisdom to have an autoformat function but not a replaceable battery!! Did Philips design these early players to be flawed :lol:

I mean as early as 1992 when SONY came out with the portable CD-i player, they had the wisdon to include an easily replaceable battery to backup the memory with. Also the later desktop non Philips brand players had a simple replaceable button battery. In fact everything non Philips seemed more robust in design and technology.

Posted: Wed Jul 27, 2005 9:58 pm
by Erronous
The reason for the autoformat function is very simply, it reduces production costs. When making a CD-i player, you can just put in a blank NVRAM from tape and put it in the player instead of having an extra production step of programming the NVRAMS which costs money.

Lots of $10.000-$100.000 workstations have the same NVRAM problems, so it is not something to blame on bad Philips design. The expected lifetime of a NVRAM chip from the datasheet is much higher than the normal lifetime of audio equipment, so I think it's hard to argue this is a big mistake. If Philips design was so bad, why did they win so many awars? For example with the cdi450....

Posted: Wed Jul 27, 2005 10:12 pm
by Devin
I'm probably being a little harsh, I just don't like the design of the earlier models, 210, 220 etc etc...that's why my collection is fairly exotic. My first player the 220 is terrible, when moving it about the disc drive falls out when even tilited slightly. Then again lots of early technology is pretty bad from the outset even to this day when DVD recorders were new as an example.

Of course i'm talking from an aeshetic perspective mostly, can you think of the last piece of retro technology that looked good? After god knows how many years the Console giants seem to have twigged this with the design for PS3, XBOX360 and the released PSP. Now the PSP, that's a nice bit of tech...I tried a colleagues console earlier in the month and that screen is very impressive. I digress!!

I'd really like to get a 740, now that's the only Philips desktop CD-i player I find desirable after the LG GDI700 and DVS VE-200.

Posted: Fri Jul 29, 2005 10:12 pm
by cdifan
I had to replace empty NVRAM chips on several SUN workstations a few years back. That wasn't fun, as the autoformat function on these machines did not produce a working boot configuration...

HowTo: Repair your Timekeeper Ram

Posted: Sat Feb 25, 2006 4:39 am
by TerraTron
Hey guys,

I wrote a HowTo: Repair your Timekeeper Ram

This could solve all of your problems....


Take a Look at it here


TerraTron

timekeeper repair

Posted: Sat Oct 21, 2006 7:54 pm
by rockclimber
Thanks Terratron,
I have just used your guide and sucessfully repaired the chip on my 205 cdi machine.
Thank you very much!! :D

Posted: Sat Oct 21, 2006 8:36 pm
by Bas
Nice! Do you have any recommendations? Parts which were tricky? Did you replace the actual part, or only used a seperate battery? How long did it took? Experiences are the most valuable thing...

timekeeper battery

Posted: Sat Oct 21, 2006 10:06 pm
by rockclimber
Hi,
I didn't replace the entire chip just the battery. It is fairly easy to do, just requires a little confidence. I used a dremel with a 2mm bit in it. But instead of drilling into the chip I used the side of the bit to par away the surface of the chip starting along the short edge of the chip. I soon found the positive wire but couldn't see the negative wire. In the end I exposed the entire top surface of the batery. The original battery lies about 0.5mm below the surface and is almost the full width of the chip in diameter. There is a solid wire (like the finger that holds a computer bios battery in ) soldered to the top of the battery that then runs down the side of the battery into the chip beneath. The negative wire is about 2mm to the left of this and approximately 3-4mm below the surface. I just used a junior hacksaw blade and cut the wire to the positive on the battery just below the level of the battery. Then I soldered a wire to the lower part of it that goes into the chip, and a wire to the exposed negative wire which I didn't cut at all. I soldered the other ends of the wire directly onto a 3v battery out of a car alarm key fob. I didn't have a battery holder because I did the repair on the spur of the moment. I can take the top of again and try to take some photos if it would help anybody.
By the way if you look at the timekeeper chip carefully you can actually see an airgap between the chip itself and the topcap section which only houses the battery at one end and a crystal at the other. So long as you only remove material from the top section you shouldn't damage the chip. Also this is the first time I have done anything like this.

Re: HowTo: Repair your Timekeeper Ram

Posted: Sun Jan 28, 2007 3:06 pm
by Calypso
URGENT

Just found out. (Battery replaced in a CDI220)

TerraTron wrote:Hey guys,

I wrote a HowTo: Repair your Timekeeper Ram

This could solve all of your problems....


Take a Look at it here


TerraTron
The pictures in this topic are not online at the moment.
A link in this topic refers to http://www.gametronik.com/forum/index.p ... topic=8406 .

On this french forum is a pdf "book" with pictures of how to replace the time keeper battery http://www.gametronik.com/forum/index.p ... st&id=9772 .

The polarity of the wires in this "book" is wrong.
The red wire + needs to be black - and the black wire - needs to be red +.

However the battery in the picture is connected correctly.
The outer contact of the battery is the positive + the inner contact is the minus -. Thats why it did work.

When the wires are cross connected, the battery gets shorted 0,7 V


Calypso

Medical Elektronics Engineer
CDinteractive.co.uk
Member of the Blackmoon Project team

Posted: Sat Mar 31, 2007 12:26 am
by TerraTron
Sorry guys,

But the pics whre away for a long time because the lemondeducdi.com server was shut down....

But the Guide is now online again...

Look here!